Process for treating magnesium-bearing ores

Abstract

It is described a process for extracting magnesium from magnesium-bearing materials comprising the steps of leaching the magnesium-bearing material with HCl as to obtain a leachate comprising the magnesium in solution and a solid form; purify said leachate to produce magnesium chloride and electrolysing the magnesium chloride producing magnesium metal.

1 . A process for extracting magnesium metal from a magnesium-bearing material, said process comprising:
 a. leaching the magnesium-bearing material with HCl as to obtain a leachate containing magnesium chloride; and   b. electrolyzing the magnesium chloride for extracting magnesium metal.   
     
     
         2 . The process of  claim 1 , wherein the step of electrolyzing the magnesium chloride comprises using an electrolysis cell having a cathode and an anode wherein a source of hydrogen gas is delivered to the anode. 
     
     
         3 . The process of  claim 2 , further comprising the step of dehydrating magnesium chloride contained in the leachate before the step of electrolyzing the leachate containing magnesium chloride to obtain magnesium metal. 
     
     
         4 . The process of  claim 3 , wherein a two step fluidized bed is used for dehydrating the magnesium chloride. 
     
     
         5 . The process of  claim 4 , further comprising a drying step in a fluidized bed dryer followed by gaseous HCl drying to extract anhydrous magnesium chloride. 
     
     
         6 . The process of  claim 5 , wherein the dehydrated magnesium chloride is further dissolved in molten salt electrolyte. 
     
     
         7 . The process of  claim 1 , wherein dry hydrochloric acid is added to proceed with the dehydration step. 
     
     
         8 . The process of  claim 1 , further comprising recycling said gaseous HCl by contacting it with water so as to obtain a composition having a concentration of about 25 to about 45 weight % and using said composition for leaching. 
     
     
         9 . The process of  claim 8 , wherein said magnesium-bearing material is leached with HCl having a concentration of about 20 to about 45 weight % at a temperature of about 60 to about 125° C. 
     
     
         10 . (canceled) 
     
     
         11 . The process  claim 8 , wherein said recycled gaseous HCl so-produced is contacted with water so as to obtain said composition having a concentration between 25 and 36 weight %. 
     
     
         12 . (canceled) 
     
     
         13 . The process of  claim 1 , further comprising the step of passing the leachate on a chelating resin system to recuperate nickel chloride from said leachate. 
     
     
         14 . (canceled) 
     
     
         15 . The process of  claim 13 , further comprising the step of electrolyzing the nickel chloride to obtain nickel. 
     
     
         16 . The process of  claim 1 , further comprising the step of hydrolysis at low temperature of about 155 to about 350° C. the leachate to extract hematite. 
     
     
         17 . The process of  claim 16 , further comprising the step of passing the hydrolyzed leachate on a chelating resin system to recuperate nickel chloride from said hydrolyzed leachate. 
     
     
         18 . (canceled) 
     
     
         19 . The process of  claim 1 , further comprising the step of supplementing at least one of MgCO 3 , H 2 SO 4 , and MgSO 4  to the leachate and purifying said supplemented leachate to recuperate CaCO 3  and/or CaSO 4 . 
     
     
         20 . The process of  claim 13 , further comprising the step of separating a liquid phase from a solid form of the leachate and concentrating said liquid phase to a concentrated liquid having an iron chloride concentration of at least 30% by weight; and then said iron chloride is hydrolyzed at a temperature of about 155 to about 350° C. while maintaining a ferric chloride concentration at a level of at least 65% by weight, to generate a composition comprising a liquid and precipitated hematite, and recovering said hematite. 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . The process of  claim 1 , further comprising a step of magnetic separation of the magnesium-bearing material before step a) of leaching to recover magnetite. 
     
     
         24 . The process of  claim 1 , further comprising the steps of oxidizing reacted leachate and crystallizing said reacted leachate to recover Fe 2 O 3  and AlCl 3 . 
     
     
         25 . (canceled) 
     
     
         26 . (canceled) 
     
     
         27 . (canceled) 
     
     
         28 . (canceled) 
     
     
         29 . (canceled) 
     
     
         30 . The process of  claim 1 , wherein the magnesium-bearing material is a magnesium-bearing ore. 
     
     
         31 . (canceled) 
     
     
         32 . The process of  claim 1 , wherein the magnesium-bearing material is an asbestos mine tailing. 
     
     
         33 . (canceled) 
     
     
         34 . (canceled) 
     
     
         35 . (canceled) 
     
     
         36 . (canceled)